The disclosure of Japanese Patent Application No. 2000-258969 filed on Aug. 29, 2000, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of Invention
The invention relates to a vehicle operation control method and apparatus during deceleration of a vehicle.
2. Description of Related Art
In a running control apparatus described in Japanese Patent Application Laid-Open No. 9-323628, during braking, a target deceleration is determined based on at least one of the distance between the vehicle and another preceding vehicle and a relative speed therebetween. The target deceleration is increased as the inter-vehicle distance is decreased, and is increased as the relative speed increases.
If the target deceleration is determined based on at least one of the inter-vehicle distance and the relative speed as mentioned above, the target deceleration continuously changes with changes in the inter-vehicle distance and the relative speed, and the deceleration of the vehicle is correspondingly changed. If the frequency of changes in the deceleration is great (i.e., the deceleration changes highly frequently), an uncomfortable feeling is experienced by an operator.
The invention has been accomplished in view of the aforementioned problem. It is an object of the invention to reduce the uncomfortable feeling given to an operator of a vehicle when the vehicle is decelerated by a vehicle operation control apparatus. The vehicle operation control apparatus controls a running state of the vehicle based on a relative positional relationship between the vehicle and another preceding vehicle running in a predetermined set area ahead. This object is achieved by constructing a vehicle operation control apparatus as described below.
In accordance with the invention, the vehicle operation control apparatus controls the running state of an vehicle based on the relative positional relationship between the vehicle and a preceding vehicle running in a predetermined set area ahead of the vehicle. The running control apparatus includes a controller that determines a target deceleration of the vehicle, controls a deceleration of the vehicle so that the deceleration of the vehicle approaches the target deceleration and maintains the target deceleration determined until a predetermined condition is satisfied.
Furthermore, a control method for controlling a vehicle operation state of a vehicle based on a relative positional relation ship between the vehicle and a preceding vehicle running in a predetermined set area ahead of the vehicle is determined. The control method determines target deceleration of the vehicle, and the deceleration of the vehicle is controlled so as to approach the target deceleration. The determined target deceleration is maintained until a predetermined condition is satisfied.
In the running control apparatus and the control method described above, the determined target deceleration is maintained until the predetermined condition is satisfied. That is, the same value of the target deceleration is maintained until the predetermined condition is satisfied. Until then, the speed of the vehicle is reduced at a constant deceleration. Therefore, the frequency of changes in the deceleration can be reduced, and the uncomfortable feeling to an operator can also be reduced.